Effect of Chelators on the Removal of BTA in Post-Cmp Cleaning

During Cu CMP process, BTA is widely used as a corrosion inhibitor. After Cu CMP process, the residual BTA leads to hydrophobic copper surface, which seriously affects the device stability. Therefore, BTA, as the main organic residue on Cu surface, needs to be effectively removed in the post-CMP cleaning process. In this paper, the removal of organic residual contaminants BTA on polished copper surface by different concentrations of chelating agent FA/OII and ethylene diamine tetraacetic acid (EDTA) was studied. The removal of organic residues was characterized by contact angle measurement and electrochemical techniques. The results show that the cleaning effect of 2mM EDTA is better than 200ppm FA/OII.